The present invention relates to certain derivatives of 4(3H)-oxobenzo-2,1,3-thiadiazine-2,2-dioxide each having various substituents on both of the thiadiazine nitrogens. This invention also relates to compositions and methods of using new derivatives of 4(3H)-oxobenzo-2,1,3-thiadiazine-2,2-dioxide as herbicides.
The prior art includes U.S. Pat. Nos. 3,041,336 and 3,217,001 which disclose certain 4 (3H)-oxobenzo-2,1,3-thiadiazine-2,2-dioxides and -2-oxides, bearing halogen, nitro or loweralkylsulfamoyl substituents on the phenyl ring which have utility as pharmacological agents. Such prior art does not disclose herbicidal utility. The use of 3-(lower alkyl)herbicides is disclosed and claimed in U.S. Pat. No. 3,708,277 and in French Pat. No. 1,538,698. It is also disclosed in German Patent Application No. P2,355,113.5 laid open May 15, 1975, that certain 1-(alkoxyalkyl)-3-alkyl-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxides are useful herbicides.
An object of the present invention is to provide certain derivatives of 4(3H)-oxobenzo-2,1,3-thiadiazine-2,2-dioxide which have good herbicidal properties. Another object of the present invention is to provide a method for controlling unwanted plant growth with derivatives of 4 (3H)-oxobenzo-2,1,3-thiadiazine-2,2-dioxide and herbicidal compositions containing these compounds.